Dogs today, humans tomorrow?

Recently, according to accusations, a 15-year-old boy torched the Manchester Dogs' Home, a canine rehoming charity. Over 50 dogs died as a consequence of the blaze.  It is thought that the teenager committed this act of arson because he was previously bitten by a dog.
Some locals risked their lives in saving some of the animals. Area residents Jason Dyer and Dean Rostock charged into the burning kennel, sparing 20 dogs from death.
In the wake of the fire, the boy, who was later bailed after his arrest, was the recipient of many angry missives, including death threats. One Twitter user wrote that the adolescent arsonist "doesn't deserve protection. He deserves a very painful punishment".
Does that go a little too far, dear reader? Yes, he is fifteen and perhaps he can be rehabilitated, if he did cause the fire.
But, if it was him, then this was an act of pure evil. Please don't give me this "he only killed some dogs" claptrap.
Here's the kicker: Would this kid torch an old-age home if he clashed with a senior citizen? You have to wonder. 
Psychopaths and animal cruelty are definitively linked. Time and time again, killers from Ian Brady to the Boston Strangler, Dunblane shooter Thomas Hamilton to Mary Bell, have displayed cruelty to animals as children. Prison cells in every nation contain murderers who worked their bloodlust out on animals first.
Dr Alan R. Felthous, Professor and Director of Forensic Psychiatry at Saint Louis University School of Medicine, held studies in the 1980s that demonstrated a strong link between animal cruelty early in life to aggression against humans later on. The result of Felthous's study "showed that those men with a high rate of recurrent and serious aggression had histories of a larger number of episodes of animal cruelty in childhood in comparison with those who were non-aggressive, based on independent ratings."
The public felt intense sadness, anger and disgust at the death of innocent pets by a deliberate act of destruction.  The outpouring of support for the dogs' home was so large that police were reportedly overwhelmed by it.
It makes the threatening messages aimed at the boy easier to understand, doesn't it? We know where this might lead.  On a certain level, the abuse the boy has been receiving can be seen a subconscious way of protecting ourselves from a possibly deranged individual who could become the next Raul Moat, a crazed killer.
Although the family of the teenaged boy initially refused to move, they were eventually convinced by police to be rehoused. Is there going to be a thorough psychiatric evalution of this kid with the police involved every step of the way? Or is he just going to serve a little time in a juvenile detention home and walk back out into the world with a new identity?
Are we going to heed the danger signals, the same ones that have been a constant for the whole of human history? Or are we just going to say that he paid the price and leave him to possibly slaughter an innocent person in the future? If this kid eventually goes beserk (again), we can't say we weren't warned.
But, then, we never seem to learn from history, do we?